Conventionally, resin sealing has prevailed in the field of element sealing for electronic component devices such as transistors, IC etc., from the viewpoint of productivity, costs, etc., and epoxy resin compositions are widely used. This is because the epoxy resin is well-balanced in characteristics such as workability, formability, electrical characteristics, moisture resistance, heat resistance, mechanical characteristics, adhesiveness to an insert material, etc. In semiconductor devices having bare chips mounted thereon, such as COB (Chip on Board), COG (Chip on Glass), TCP (Tape Carrier Package) etc., liquid resin compositions for electronic components are widely used as sealing materials. In a semiconductor device (flip chip) having a semiconductor element bump-bonded directly onto a wiring substrate having ceramics, a glass/epoxy resin, a glass/imide resin, a polyimide film or the like as a substrate, a liquid resin composition for electronic components is used as an underfill material for filling a gap between the bump-bonded semiconductor element and the wiring substrate. Such a liquid resin composition for electronic components plays an important role in protecting electronic components from temperature and moisture and mechanical external force.
For providing a sealing epoxy resin composition excellent in moisture-resistant adhesion and low stress characteristic and an electronic component device having high reliability (moisture resistance, thermal shock resistance) provided with a component sealed therewith, there are disclosed a sealing epoxy resin composition comprising (A) a liquid epoxy resin, (B) a curing agent containing a liquid aromatic amine, (C) rubber particles and (D) an inorganic filler, and an electronic component device comprising an element sealed with the sealing epoxy resin composition (see, for example, Japanese Patent Application Laid-Open No. 2001-270976).